Rheem SPEX3512T

This site calculated the 615 kWh figure; it does not come from the registry. It combines the registry's UEF, the ratio of hot water delivered to energy used, with the DOE test's daily hot-water draw for the very small draw pattern. This model's registered UEF is 0.96. The inputs come from the DOE CCD, retrieved 2026-09-19. The figure describes the test day, not any particular household. A home whose daily hot-water use differs from the test draw will see a different annual figure, and this page does not have that figure. The page on how the annual energy and cost are calculated sets out each step. It shows how the registry's UEF and the test draw produce the yearly value.

This model is compared with the 271 models registered as an electric tankless unit at the very small draw pattern. Among them it ranks 77th lowest in energy use. That places it in the second-lowest quarter of its class, alongside the median match noted above. The very small draw pattern covers small units: a single bathroom, or a point-of-use heater under a sink. The registered maximum flow rate in gallons per minute is 0.3. A home that needs more than 0.3 at the same moment falls outside what this rating covers. For a larger demand, the water heater selector by fuel, space and size lists other classes. Their test conditions differ, so their annual figures are not directly comparable with this one.

This text does not state a running cost for the 615 kWh. That cost depends on your own utility's electricity tariff. So the page works it out from your ZIP instead of assuming a single rate. Under a different tariff, the same 615 kWh gives a different yearly cost. To see the figure for your address, use the running cost calculator for your own ZIP. The installed price range has its own block, with its source and date. It is a modeled installed-cost range, not a quote. To check this unit against another model, you can find a same-class replacement by model number. That comparison stays within the same class of 271 models.